doubleSel is package{
  foo(X) is valof{
    logMsg(info,"foo of $X");
    valis X+2;
  }
  
  bar(A) is case foo(A) in {
    X matching 4 is X;
    _ default is -1
  };
  
  main() do {
    logMsg(info,"bar = $(bar(2))");
    assert bar(2)=4;
  }
}